全文获取类型
收费全文 | 1659篇 |
免费 | 108篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 17篇 |
综合类 | 9篇 |
化学工业 | 558篇 |
金属工艺 | 35篇 |
机械仪表 | 30篇 |
建筑科学 | 68篇 |
矿业工程 | 2篇 |
能源动力 | 46篇 |
轻工业 | 128篇 |
水利工程 | 31篇 |
石油天然气 | 2篇 |
无线电 | 99篇 |
一般工业技术 | 310篇 |
冶金工业 | 188篇 |
原子能技术 | 6篇 |
自动化技术 | 241篇 |
出版年
2023年 | 18篇 |
2022年 | 45篇 |
2021年 | 44篇 |
2020年 | 36篇 |
2019年 | 56篇 |
2018年 | 48篇 |
2017年 | 47篇 |
2016年 | 50篇 |
2015年 | 40篇 |
2014年 | 76篇 |
2013年 | 97篇 |
2012年 | 76篇 |
2011年 | 119篇 |
2010年 | 81篇 |
2009年 | 64篇 |
2008年 | 76篇 |
2007年 | 72篇 |
2006年 | 64篇 |
2005年 | 59篇 |
2004年 | 41篇 |
2003年 | 48篇 |
2002年 | 27篇 |
2001年 | 26篇 |
2000年 | 15篇 |
1999年 | 22篇 |
1998年 | 42篇 |
1997年 | 30篇 |
1996年 | 23篇 |
1995年 | 26篇 |
1994年 | 16篇 |
1993年 | 22篇 |
1992年 | 14篇 |
1991年 | 10篇 |
1990年 | 16篇 |
1989年 | 11篇 |
1988年 | 7篇 |
1987年 | 7篇 |
1986年 | 17篇 |
1985年 | 11篇 |
1984年 | 12篇 |
1983年 | 15篇 |
1982年 | 11篇 |
1981年 | 16篇 |
1980年 | 10篇 |
1979年 | 16篇 |
1978年 | 10篇 |
1977年 | 15篇 |
1976年 | 11篇 |
1975年 | 10篇 |
1973年 | 7篇 |
排序方式: 共有1770条查询结果,搜索用时 15 毫秒
41.
Laurent Dusoulier Samuel Denis Philippe Vanderbemden Michel Dirickx Marcel Ausloos Rudi Cloots Bénédicte Vertruyen 《Journal of Materials Science》2006,41(24):8109-8114
YBa2Cu3O7-x
thick films have been realised by the Electrophoretic Deposition method (EPD). The influence of several parameters (powder and iodine concentrations in the suspension, applied voltage and deposition time) on the EPD process has been studied by measuring the conductivity of the suspension and the amount of YBa2Cu3O7-x
particles deposited on the electrode. Superconducting coatings onto silver substrates have been produced by a multilayer process during different deposition times. The highest critical current density value of these coatings measured by the four-point probe method is about 103 A/cm2 (77 K), in a suitable range for magnetic shielding applications. 相似文献
42.
43.
T. Dalgleish and M. J. Power (see record 2004-15929-012) suggest that J. A. Lambie and A. J. Marcel's (2002) article implicitly presents a unitary view of self in emotion experience and propose that certain clinical phenomena require multiple selves. This reply summarizes Lambie and Marcel's usages of the term self and examines both Dalgleish and Power's gloss of these and their own usages. This indicates that their own central usage of the term misrepresents Lambie and Marcel and is itself an improper usage. More important, examination of the phenomena claimed to require multiple selves suggests that they do not and that Dalgleish and Power may have misread the relevant clinical literature. Finally, Lambie and Marcel's own conception of dissociative phenomena and multiple selves are outlined, and alternative approaches are sketched. In discussing the usages of the term self and interpretation of cognitive and affective disorders, this reply attempts to clarify certain confusions. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
44.
Chemiresistive polymer composite ribbons that function as chemical detectors were produced from solution-cast films of polymers and carbon composites. An array with multiple polymer sensor threads was exposed to dimethyl methyl phosphonate, a nerve agent simulant, and different interferents in the vapor phase. Principal component analysis was used to differentiate between the analytes. The response of the ribbon sensors as a function of the carbon composite and the host polymer source was investigated. The freestanding threads/sensors were mounted into a cell perpendicular to the gas flow to provide little pressure drop and were imbedded into fabrics to provide an example of a small, low-cost, wearable chemical sensor. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
45.
Venkatesh Bala Subburaman Sébastien Marcel 《Computer Vision and Image Understanding》2013,117(5):551-570
The sliding window approach is the most widely used technique to detect an object from an image. In the past few years, classifiers have been improved in many ways to increase the scanning speed. Apart from the classifier design (such as the cascade), the scanning speed also depends on a number of different factors (such as the grid spacing, and the scale at which the image is searched). When the scanning grid spacing is larger than the tolerance of the trained classifier it suffers from low detections. In this paper, we present a technique to reduce the number of missed detections when fewer subwindows are processed in the sliding window approach for face detection. This is achieved by using a small patch to predict the location of the face within a local search area. We use simple binary features and a decision tree for location estimation as it proved to be efficient for our application. We also show that by using a simple interest point detector based on quantized gradient orientation, as the front-end to the proposed location estimation technique, we can further improve the performance. Experimental evaluation on several face databases show better detection rate and speed with our proposed approach when fewer number of subwindows are processed compared to the standard scanning technique. 相似文献
46.
47.
Filippo Bianchi Marcel Thielmann Roman Mani Dani Or Hans Jürgen Herrmann 《Granular Matter》2016,18(4):75
The mechanics of granular media at low liquid saturation levels remain poorly understood. Macroscopic mechanical properties are affected by microscale forces and processes, such as capillary forces, inter-particle friction, liquid flows, and particle movements. An improved understanding of these microscale mechanisms is important for a range of industrial applications and natural phenomena (e.g. landslides). This study focuses on the transient evolution of the tensile stress of unsaturated granular media under extension. Experimental results suggest that the stress state of the material evolves even after cessation of sample extension. Moreover, we observe that the packing density strongly affects the efficiency of different processes that result in tensile stress relaxation. By comparing the observed relaxation time scales with published data, we conclude that tensile stress relaxation is governed by particle rearrangement and fluid redistribution. An increased packing density inhibits particle rearrangement and only leaves fluid redistribution as the major process that governs tensile stress relaxation. 相似文献
48.
49.
50.
Freddy Boscn Marcel Meeuwisse Dirk Mestach Maria Paulis Maria Jesus Barandiaran Silfredo Javier Bohrquez 《大分子材料与工程》2019,304(7)
The benefits of polymerizing very insoluble monomers in aqueous media, avoiding the use of energy‐intensive procedures, by implementing two novel synthesis techniques based on the emulsifier combination in emulsion polymerization and on miniemulsification by phase inversion temperature are investigated. The performance of standalone polymers consisting of monomers, namely lauryl methacrylate, isobornyl acrylate, and 1H,1H,2H,2H‐perfluorodecyl acrylate, and of formulated binders with these monomers incorporated either through blending or in situ polymerization, is evaluated with special emphasis on their water‐barrier properties (e.g., uptake, whitening, immersion, and vapor resistance) and on their chemical resistance. The performance of the standalone polymers is found to be similar to that of polymers prepared by high‐shear miniemulsion polymerization, while the performance of the formulated binders is generally superior to a commercial coating formulation based on a binder recommended for water resistance. 相似文献